Year Percent 1950 30.3469 1955 29.31435 1960 28.02105 1965 27.42274 1970 27.11082 1975 27.96757 1980 28.68076 1985 29.47466 1990 30.21207 1995 31.49596 2000 32.81204 2005 34.10544 2010 35.30386 2015 35.36039 2020 35.0181 2025 33.80746 2030 32.61373 2035 32.11403 2040 31.84991 2045 31.5833 2050 31.03314 2055 30.12145 2060 29.28114 2065 28.59558 2070 28.01718 2075 27.46087 2080 26.86203 2085 26.26195 2090 25.7313 2095 25.29117 2100 24.94023